Refund rights and obligations are regulated in USA by Fair Trading Act 1999 and the Trade Practices Act
1974.

According to these laws:A customer has a right to ask for a refund if the goods:

• do not do the job the customer was led to believe they would (the
product is unfit for its purpose)• have a fault that the customer could not have known about at the
time of purchase• do not match a sample the customer was shown are not as they were
described

Rights of traders:Trader doesn't have to provide the refund if:

• no proof of purchase is offered• the customer simply changes their mind• the customer finds the good cheaper elsewhere• the customer knew of a particular fault before buying the goods• the goods were damaged after the purchase, unless the damage is a
result of the normal, recommended use of the goods